1. Field of the Invention
This invention relates to elastomeric poly(aryloxyphosphazene) homopolymeric and copolymeric compositions, to flexible and semirigid foams produced from said homopolymeric and copolymeric compositions, and to a process for preparing these materials. These compositions exhibit excellent smoke suppressant properties as a result of having incorporated therein an effective amount of a normally solid carboxylic acid. Foams prepared from the compositions also produce low smoke levels, or essentially no smoke, when heated in an open flame. All of the homopolymeric and copolymeric compositions described may be cross-linked at moderate temperatures in the presence of free radical initiators, and the copolymers containing reactive unsaturation additionally may be cured by conventional sulfur curing or vulcanizing additives to modify their properties and expand their field of use.
2. Description of the Prior Art
The preparation of poly(aryloxyphosphazene) polymers has been disclosed in U.S. Pat. No. 3,856,712 to Reynard et al; U.S. Pat. No. 3,856,713 to Rose et al; and U.S. Pat. No. 3,883,451 to Reynard et al. The copolymers described in the first-mentioned Reynard et al patent contain selected quantities of both alkoxy and aryloxy side chains in the copolymer backbone, whereas the copolymers described in the latter-mentioned Reynard et al patent are characterized by the presence of halogen-substituted aryl side chains in the copolymer backbone. Other related art may be found in U.S. Pat. Nos. 3,515,688; 3,700,629; 3,702,833; 3,856,712; and Ser. No. 661,862 filed Feb. 27, 1976.
Many of these prior art homopolymers and copolymers are noted for their high smoke-forming properties which severely limits their range of application.